The basic steps of the FHM
In terms of storage tanks in Rotterdam, the stated aims of the risk assessment (Steps 2 and 3) are to:
- Minimize the risk of loss of containment (i.e. product or vapour release)
- Minimize the risk of a fire or explosion occurring on or in the tank itself
- Mitigate the consequences of such an incident, particularly with regard to people and the environment
- Protect the tank from fires occurring elsewhere.
Tank fire scenarios and corrective actions
Causes of ignition
- Lightning strikes
- Hot work on live tanks
- Flare stack fall-out
- Over heat or mixer failures
- Over-fill with remote ignition sources (Buncefield)
- Floating roof contact with tank shell
- Build-up of static electricity.
Reducing the likelihood of ignition
- Secondary seals for high vapour pressure products
- Fire retardant rim-seal materials
- Independent high level alarms
- Linear heat detection in the rim-seal
- Wind girders with handrails, to facilitate inspection of seal areas, and foam application to the seal area. Open top or external floater tanks are designed with a stiffening ring (commonly known as a wind girder) to add support, due to the absence of a roof.
- Proper system maintenance.
Resource requirements for larger (>40 m) diameter tanks
For a ground level foam attack on a tank full surface fire, it is important to realize the following:
- It is not an exact science, each fire may differ due to weather conditions, the fuel involved, etcetera
- Provide the tools and the knowledge to keep options open
- Be aware of the extremely large quantities involved! Foam Pumping Appliances and foam procurement (some 100,000 litres of foam concentrate needed per hour of firefighting) and Water Supplies (approximate 3.5 million litres of water needed per hour of fire-fighting) must be met. The capacity of any water pumping appliances, being used for water monitor supply, must be as large as possible. Typical “standard” water tenders/pumpers may only have a 2,500 L/m pump on board. Obviously, this will only be enough for 1 typical water monitor, and if larger water monitors are used, then it may require 2 or more water pumping appliances, for every monitor. This can lead to major logistic and deployment challenges.
- Large tank incidents may involve more than 100 firefighters and during the fight, fatigue due to physical effort and manual handling of hoses and equipment is likely to play a major role. Additionally, a long duration usually introduces catering and backup needs.
- A major item to consider, when fighting fire, is wind direction! Not only in regard to the difficulty in getting the water foam mixture in the right place, but also with visibility, which may be reduced due to dense black smoke, resulting in firefighters being exposed to slips and falls.
Normal municipal fire brigades are not equipped, nor trained, to handle or adequately respond to these types of large chemical fires. A main criterion is the time needed to reach the incident site, which is now defined as being within 10 minutes. Thus the Unified Fire Brigade (GB) was formed and became operational in 1998. It is a fully equipped professional fire brigade that is able to handle chemical fires and is part of the Industrial Firefighting Pool or Industriële Brandbestrijdingspool (IBP). It is manned 24/7 and staffed by 300 qualified employees.
Unified fire brigade (GB) The Unified Fire Brigade (Gezamelijke Brand weer) was formed to adequately protect the large industrial area to the west of the city of Rotterdam. This area is some 35 kilometres long and some 2 to 5 km wide and comprises Rotterdam Waalhaven, Pernis, Botlek, Rozenburg, Europoort, Maasvlakte 1 and Maasvlakte 2. Here, we find an impressive mix of industrial activities that are not restricted to the harbour, such as logistic service providers, as well as an impressive mix of chemical plants, ranging from oil refineries to fertilizer plants, specialty chemicals manufacturers and power plants.
All big names like Shell, Exxon, Akzo Nobel, Neste, Unilever, Dupont, BASF and DOW have plants in this area. Moreover, the available tank storage capacity is one of the largest in the world. The area is Europe’s most concentrated region of oil and chemical, storage and processing facilities. Facilities include crude oil import and transfer terminals, refineries, petrochemical processing plants, chemical storage depots and plastics manufacturing facilities. Consequently, it contains a massive number of storage tanks, containing a wide variety of materials.
Storage tanks may contain large volumes of flammable and hazardous chemicals. A small accident, here, may lead to a multi-million euro property loss and a few days of production interruption. A large accident could result in lawsuits, stock devaluation or may even lead to company bankruptcy. That is why we, at If, put great emphazis on the importance of proper levels of incident (loss of containment and fire) prevention measures and proper protection.
The GB objectives
- Performing, maintaining and renewing industrial and public fire services, in its service area, which may arguably be comparable to similar organizations around the world, in terms of efficiency, quality and service.
- Fighting incidents through an organization of specialized industrial firefighters, whose core purpose is swift intervention.
- Providing assistance, in the broadest sense, with non-fire disasters.
Or in other words; it comes down to performing the following tasks: the rescue of humans and animals, fighting building, unit and tank fires and "chemical spills", plus technical assistance.
The following special appliances are available:
Two 37,500 L/m monitors that include individual diesel driven pump sets (for fighting tank fires of up to 80+ meters in diameter and tanks up to 22 meter high) using a driven booster pump with a capacity of up to 80,000 L/m at 10.5 bar diesel, which combined, allow for a longer water supply distance. In addition, special large hose reels and re-reeling equipment are included.
Water is supplied by two Rotterdam Port Authority patrol boats or incident fighting vessels via eight diameter hoses.
Sufficient synthetic, alcohol-resistant AFFF foam concentrate is available, on site, on fire fighting vehicles and in small containers (60 m3 in total), as well as in six hook-arm containers of 20 m3 each. The combination of all of this equipment, along with the trained fire fighters, should enable them to succesfully fight tank and tank bund fires.
For tank bund fires, a special sector driven approach was developed, where the tank bund is divided into imaginary sectors and each sector is approached in succession, one after the other, whilst the foam blanket is maintained on earlier sectors and water is supplied by the RPA. Special equipment was acquired, at an additional cost of some € 300,000, to facilitate this.